The first part of the study will utilize the acrylamide gel electrophoresis patterns (AGEP) of gonococcal cell proteins as a "fingerprint" to identify subtypes of this species. Comparisons will be made between the AGEP of gonococcal isolates, strains of non-pathogenic Neisseria and related genera. The stability of the AGEP from gonococcal cell proteins will be tested for the impact of environmental changes as serial passage and time of incubation. In addition, correlations will be made between the AGEP and colonial morphology. Also, an AGEP will be sought that identifies pili production by the organism. Gonococcal strains associated with particular virulence or tissue tropism will be identified using AGEP. The second part of the study will utilize antigens isolated in sections of the electrophoresis gels which will identify the human antibody response to gonococcal infection. The third part of the study will compare the AGEP from gonococcal strains to identify a common antigen suitable for a serological screening test. This antigen will undergo chemical and physical analysis and be tested in a field trail for its ability to identify antibody in patients infected with the gonococcus.